Hello,
I'm given to understand that the shortage of Glock pistols in the U.S. commercial market right now is mainly attributable to Glock giving priority to other contracts. The UK Ministry of Defense just adopted the Glock 17 as its primary pistol (some 25K+ of them), and I think the US DOJ contract is still in full swing as well. I've been told that distributors can't get their hands on Glock pistols because the company is trying to fill these contracts first, and has reduced the supply of pistols to the commercial market. Combined with the increased demand of the current market, the result is an extreme shortage of Glock products here in the US.
Regarding the Tenifer vs Melonite debate, I understand that these are both the same process ("salt bath ferritic nitrocarburizing"), but due to licensing issues, the "Tenifer" label is used in Europe and the "Melonite" label is used here. Since salt bath nitriding is common here in the US, I'm suspicious of the claim that the "Tenifer" process is banned by the EPA.
It's also my understanding that the Tenifer process is a hardening process, a metal "treatment," and not a "finishing" process. I'm no chemist, but it's my understanding that the Tenifer / Melonite process is essentially adding nitrogen and carbon to the metal at very high temperatures (yet, below the "critical" point of the steel), to make the metal harder after it cools. When this process is done, the physical makeup of the metal is different.
After the Tenifer process is done, then a finish is actually applied to the parts. On the Glock, the Tenifered barrel is blued and (until recently) the Tenifered slide is parkerized (newer pistols are now being finished by some other process which leaves a smoother, dull gray, surface).
If you see surface wear on a Glock, then it is simply the finish (parkerizing or the new dull gray finish they are using) wearing through. If the wear is bad enough, you might get down to the raw, Tenifer-treated steel, but that doesn't represent a failure of the Tenifer, just a failure of the parkerizing which was applied on top of the Tenifer-treated steel.
At least that's how I understand it. I'm willing to be corrected if I'm wrong.
I'm not familiar with the complaints about rusting that BillT mentioned in the XDs and S&Ws, but if there is a difference between these guns and the Glocks, I'm not sure it is related to Tenifer versus Melonite. There may be some other explanation here, such as:
1. A difference in the finish being applied to the slides on those guns after the Tenifer / Melonite process is complete--perhaps the S&W / XD finish is not as durable as the surface finish being applied to the Glock slides, so the underlying steel is being exposed more quickly?
2. A difference in the way the Tenifer / Melonite process is performed--skill and attention to detail?
3. A difference in the underlying steel. I understand that the Tenifer/Melonite process is not as effective on Stainless Steel (used by S&W on the M&P slide) as other steels. Perhaps this could account for an increased chance of rust on the S&W versus the Glock?
I'm assuming that the rust complaints you referenced are about the slide--is that correct BillT? Otherwise, if the complaints are about barrels or other internal parts rusting, then that's just a case of rust on blued steel, which is not unusual, and has nothing to do with Tenifer vs Melonite.
V/R
Mike